1. Field of the Invention
The present invention relates to camera-obtained imagery captured from a moving vehicle.
2. Related Art
A camera, such as a panoramic camera, can be mounted on a vehicle, such as a car, truck, van, or any kind of vehicle, and used to capture images as the vehicle moves. A panoramic camera is a camera, typically a system of one or multiple cameras, that is configured or arranged to capture a panoramic image (i.e., an image or view of an area in many directions, possibly every direction). Examples of a panoramic camera can include a single camera, a polycamera, a camera rosette, a rotating camera, etc. The captured images may be used for online navigation and viewing tools such as Google Inc.'s STREET VIEW tool, for example. Vehicles that use panoramic camera systems in this manner may also include other systems and devices for related data collection. For example, a data collection vehicle may include a Global Positioning System (GPS) and/or an Inertial Measurement Unit (IMU) sensor in addition to the camera system. It may also record the amount of rotation of the vehicle's wheels. These systems include sensors that can collect data, which can help estimate the location of the vehicle. Given the precise location of the vehicle, the captured images can be associated with and shown at those locations.
There is nontrivial variation in the way a panoramic camera system and GPS and IMU sensors are placed on, or within, a data collection vehicle. For example, there is little consistency in the placement of a camera rack on top of the vehicle roof. In addition, there is variation in how and where the GPS and IMU sensors are placed within the vehicle. Furthermore, cameras and camera racks are often replaced, or their configuration and/or positioning may be changed by human operators. In many applications, in order to correctly render a panoramic view, one needs to know how the ground plane and world coordinates relate to the image panorama that was captured by the panoramic camera. If this information is not known or inaccurate, objects (e.g., buildings) and their surroundings may appear incorrectly, e.g., tilted to one side. Furthermore, directional arrows that may be used in a viewing tool may point in a wrong direction. Thus, knowing the camera orientation relative to GPS and/or IMU sensors in a data collection vehicle can be important.